Are protocols inheritable in Objective-C?

Posted by aquaibm on Stack Overflow See other posts from Stack Overflow or by aquaibm
Published on 2010-06-04T06:01:40Z Indexed on 2010/06/04 6:09 UTC
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Filed under:

objective-c

|

cocoa

I saw this in some header file in the framework directory:

@interface NSCharacterSet : NSObject <NSCopying, NSMutableCopying, NSCoding>

@end

@interface NSMutableCharacterSet : NSCharacterSet <NSCopying, NSMutableCopying>

@end

I thought protocols were inheritable.If I am right about that,There is no need to type <NSCopying, NSMutableCopying> again after "NSMutableCharacterSet : NSCharacterSet".And NSMutableCharacterSet also conforms to NSCoding protocol, right?

Than why is Apple typing that again?Am I making mistake?

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